BMS : Building Management System

A Building Management System (BMS), also known as a Building Automation System (BAS), is a computer-based control system installed in buildings that control and monitor the mechanical and electrical equipment of the building, such as ventilation, lighting, and power systems, fire systems and security systems. A BMS consists of software and hardware; the software program, usually configured in a hierarchical way, can be proprietary and use protocols such as C-Bus, Profibus, etc. Suppliers are also producing a BMS that integrates the use of Internet protocols and open standards such as DeviceNet, SOAP, XML, BACnet, LonWorks, Modbus or KNX.

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BMSs are commonly implemented on large projects with extensive mechanical HVAC and electrical systems. Systems linked to a BMS typically account for 40% of a building's energy use; if lighting is included, this number approaches 70%. BMS systems are a critical component in managing energy demand.

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In addition to controlling the internal environment of the building, BMS systems are sometimes linked to access control (turnstiles and gates that control who can enter and exit the building) or other security systems such as Closed Circuit Television (CCTV) and motion detectors. Fire alarm systems and elevators are also sometimes linked to a BMS for monitoring. In the event of a fire being detected, only the fire alarm panel could close the dampers in the ventilation system to stop the spread of smoke, turn off the air handlers, turn on the smoke evacuation fans, and send all the elevators to the ground floor and park them to prevent people from using them.

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